1. Field of the Invention
The invention relates to audio-visual ("A/V") devices, specifically to "deferred recording" devices for repeating A/V episodes from an A/V device. A/V devices, such as radios or television receivers, are often used in environments where momentary distractions or signal distortions can cause the user to miss a received signal episode.
2. Problem Description
While using a radio receiver in a noisy local environment, a user may miss, i.e. not completely comprehend, an important broadcast A/V signal episode. This often occurs with the use of automobile radios where the driver may be distracted during important broadcast moments like traffic reports, telephone numbers or sports scores. Similarly, a user may miss a received signal that has been degraded by transmission path effects or by electromagnetic interference. In the case of two-way radios used in conjunction with public transportation, a missed radio signal can affect the safety of the vehicle and passengers. Examples include the use of radios by aircraft, ship, and train crews. To illustrate, an aircraft pilot may miss an important air traffic voice communication due to either a distorted signal or a local distraction. One or more playbacks of a slightly distorted received signal would often enable a user to fully understand the missed episode. It would be useful for the user to be able to ask "What?" of the device and if the device is manually actuated within a reasonable length of time, i.e. within a few seconds of the beginning of the missed A/V episode, to repeat exactly what had been received in the moments before and after activation of a record switch. In the use of telephones, it is often useful to record and store telephone numbers as they are recited into the telephone. In the use of digital note-recorders and cassette recorders in classroom or conference situations, it is often useful to restrict recording to only selected A/V episodes. Additionally, it is useful to briefly defer the recording of an episode until after the A/V episode has transpired and has been heard/viewed and evaluated by the user. Regarding the content of the recorded episode, it is often important that the A/V segment following the actuation of a record switch also be recorded. That following segment, known as a "postamble", often adds useful context to the preceding "preamble" segment. In many cases that recorded preamble segment alone would be inadequate to facilitate full comprehension by the user.
3. Prior Art
Some common A/V devices can record a live received signal episode for later playback. Originally, such devices could record only the signal segment received after a record switch was pressed and the signals received prior to a user pressing a record switch were lost. Consequently, the user first had to anticipate that he/she would need to record a future signal episode. This was usually not practical since the user must first hear/view and evaluate the received signal prior to being able to decide whether to record it. A "deferred record" capability was needed which would allow the user to defer pressing the record switch until after the user had first viewed/heard the earlier segment of the live A/V signal.